Skilled worker to ILR but with a single day of unauthorised absence

Hi,
My Australian partner is currently here on a skilled worker visa and is going through the 5 year ILR application process at the moment. They are very comfortably under the 180 day in 12 month rolling window criteria, but we are a little unsure of how to handle the evidence from their employer (the NHS) regarding absences. As per the advice given on various other threads on the forum, a separate letter from their employer which specifically addresses absences is not required as long as the employer confirms that all leave taken by the individual was authorised. However, what happens in the case that there was unauthorised absence? My partner has a single day which is not authorised which i believe was due to some flight related issues on a holiday meaning they had to come back a day later than expected.

How likely is it that this one day impacts the application? And is it even necessary to provide the letter from the employer which will show this in the first place?

This is extreme overthinking and nitpicking. There is nothing in the immigration rules that suggests such details are even relevant. The advice you have seen before applies here.

All you need to know about the sponsor letter for Skilled Worker route